Brake control apparatus



Oct. 22, 19

W. R. FREEMAN BRAKE CONTROL APPARATUS Filed March 9, 1932 Fig.1

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Patented Oct. 22, 1935 PATEN'II OFFICE lBRAKE CONTROL APPARATUS Walter-AR. Freeman, Jay, Okla., assignor to Mid- West Engineering Corporation, Tulsa, Okla., a corporation of Oklahoma Application March 9, 1932, Serial No. 597,674

10 Claims. (Cl. 192-4) My invention relates to braking apparatus and especially to the control of the vehicle brakes by the brake and clutch pedals and the change speed transmission mechanism of the vehicle.

' In motor vehicles which are equipped with means controlled by the clutch pedal for maintaining the brakes in applied position, as for example, the meansV disclosed in Patent No. 1,800,- 520 issued April 14, 1931 to Ernest H. Schweering and myself, the normal operation in stopping the moving vehicle at a desired point, as for instance in parking or at a street intersection, is to leave the transmission in gear, release the clutch, and apply the brakes. As long as the clutch is released, the brakes will be maintained in their applied position and, therefore, if the brakes have been applied with too great a force, the vehicle will be stopped before it reaches the desired point unless the clutch is reengaged to release the brakes. tion to avoid this diiliculty and since the transmission is generally in its ,second" or high gear when bringing the vehicle to a stop, I achieve this object by providing means whereby the clutch operated brake holding means will be inoperative when the transmission gears are in second or high gear relation.

will disclose my invention as applied to ve? hicles equipped with clutch control means for hydraulically actuated brakes, but it is to be understood that the invention may be applied equally well to vehicles equipped with mechanically actuated brakes and with means for holding the brakes in applied position.

In the accompanying drawing Figure i is a side view oi my improved control attachment in its assembled relation with the hydraulic brake applying means, the clutch pedal, and the transmission of the vehicle; Figure 2 is a view, partly in cross section, of the braking system, the control valve, and its connection with the gear shifting mechanism of the transmission; Figure 3 is a cross sectional view on the line 3 3 of. Figure 2; Figuresd and 5 are detail views of the structure disclosed in Figure 2; and Figure 6 is a view on the line 6-6 of Figure 2.

Referring to the drawing, i indicates the engine of a motor vehicle which is connected by means oi a clutch 2 and a change speed transmissionv 3 to the road wheels of the vehicle for supplying power thereto inthe well known manner. The clutch 2 is operated by the clutch shaft l and the clutch pedal 5, the clutch being disengaged when the pedal. is in depressed position, as shown in Figure 1. The brake pedal t It is the object of my invenp is pivotally mounted on the clutch shaft and is connected by the thrust member 1 with the com-` pressor unit 8 of an hydraulically actuated brake system. The compressor unit is mounted on a frame portion 9 of the vehicle and is composed of 5 the usual cylinder ill and piston il and is connected through my novel control valve I2 and by suitable conduits to the brake applying cylinders it of the wheel brakes i4.

My novel control valve i2 comprises a threaded l0 extension i5 screwed into the end of the cylinder it, the extension being provided with a bore i6 communicating with a chamber il which in turn communicates by means of an opening it with a second chamber i@ connected to the brake cyll5 inders. The ope it is controlled by a valve t@ biased against its seat 2i by a spring 22. The stem 23 of the valve extends through the opening it into the chamber Ail and is provided with a headedend 2d for cooperation with a pair 20 of valve controlling cams to be presently described. In order to allow liquid to flow through the opening it, the valve stem is provided with a plurality of longitudinally extending grooves 25. The valve is also provided with a rubber 25 washer 26, attached thereto by means of a groove in the valve stern, for preventing leakage of iluid between the valve and its seatwhen the valve kis closed.

A pair of shafts 2l and 2t extend into the chamber il from opposite sides thereof and at right angles to the valve stem. The adjacent ends of these shafts are each provided with a cam cooperating with the headed end 2t ofthe valve stem. The cam 2S on the shaft 2l is provided with a ilattened surface and the cam Sil on the shaft 2t is provided with a curved surface and when they are in the position shown in Figure 2, they allow the spring 22 to seat the valve. A spring 3i is interposed between the shafts for biasing the shafts against the packing glands 32 screwed into the housing of the valve.

The end oi the shaft 28 which projects out of the valve housing, is provided with an arm 33 which is connected by an adjustable rod 34 with the clutch pedal E. The length of the arm 33 .and .rod tt are so proportioned that when the lclutch pedal is depressed, as shown in Figure 1, to disengage the clutch, the shaft 2B and cam 30 willl be rotated to such a position as to permit the valve to seat if allowed to do so by the cam 29. When the clutch pedal is in clutch engaged position, the position of the cam 30 will be such as to lift the valve from its seat against the action of the valve spring 22. 66

The end oi! the second and high gear selecting rod which extends out oi' the transmission housing, is provided with'a laterally extending arm 39 connected by means of a ball joint to a rod 4U. of the transmission and is connected to the short arm 4l secured to the outer end of the cam shaft 21. The length oi' arm 4| is so proportioned to the travel of the rod 3l, that when the rod 35 is in either of its gearlengaging positions, the cam 29 will hold the valve ofi its seat. When the rod 35 is in its neutral position, as shown in Figure 1, the cam 29 will be in such position as to permit the valve to seat if allowed to do so by the cam 30.

In operation, when the gear shift lever 3T is in its neutral position, or in a position to have operated the rst and reverse gear rod 3B, the cam 29 is in the position shown in Figures 2 and 4', permitting the valve 20 to-be operated solely by the cam 30 controlled by the clutch pedal. If, under these conditions, it is desired to stop the vehicle and maintain the brakes applied without maintaining pressure on the brake pedal, as for example during a trafilc stop on an incline, the clutch would be ilrst disengaged, thereby rotating the cam 30 to such a position as to allow'the valve to be seated by the spring 22, and then the brakes applied. The uid under pressure created by movement of the piston Il, will automatically unseat the valve against the action of the valve spring and apply pressure to the brakes. 'I'his pressure will be maintained without the necessity of holding the foot upon the brake pedal since the valve will immediately be reseated by the spring as soon as the piston pressure is released. When the clutch pedal is reengaged, the cam 30 will be rotated to unseat the valve and release the brakes. The operator will, therefore, be able to engage the clutch and release the brakes by the use of only one foot, allowing the other foot to be free to actuate the accelerator to speedup the engine to start the vehicle promptly.

If the transmission is in high or second gear, as is usually the case when the vehicle is moving, and it is desired to stop, the cam 29 will be in a position to maintain the valve open against the spring 22. Under these conditions, the braking system will operate in the same manner as it would if the valve were not in the system. The movement of the clutch pedal will have no effect upon the valve and, therefore, when the clutch is disengaged, the brakes are controlled solely by the pressure on the brake pedal and the vehicle may be stopped at any desired point by the proper manipulation oi' the pedal in the usual manner.

From the above description it is seen. that I have eliminated the control of the brakes by the clutch pedal when the transmission is in high or second gear, thus' permitting the operator to freely manipulate the brakes in stopping'the lvehicle in traflic or at a trafiic stop signal, and by placing the transmission in neutral or in 10W The rod 40 extends downwardly alongside` gear, preparatory to starting again as soon as allowed, the clutch control of the brakes is ren-r dered eilective, whereby the operators foot may be moved from the brake pedal to the` accelerator without thereby releasing the brakes. 5 l

Having fully described my invention, what I claim as new and desire to secure by Letters Pat-l ent of the United States is: l

1. In apparatus of the class described, the combination o! a iluid brake mechanism and a 10 shifting mechanism ior a change speed gearing, valve means for holding thebrake applied, and means operated by the sluiting mechanism when it is in its high speed or next to high speed posi- Ation to render the holding means inoperative. said l5 means being inetlective under other positions of the shifting mechanism. v

2. In a vehicle provided with clutch and brake mechanisms and a shifting rod 'for selecting the second and high speed.v gear ratios of a change I0 speed gearing and with means actuated by thel clutch mechanism for holding the brakes applied, means actuated by the shii'tin'grod when it is'k brought to its second or high speed gear ratio position to render the holding means inoperative. M

3. In a vehicle provided with brake mechanism and a shifting rod for selecting the second and high speed gear ratios of a change speed gearing and with means for holding the brakes applied, means actuated by the shifting rod when it is 80, brought to its second or high speed gear ratio position to render the holding means inoperative.

4. In a vehicle provided with a viluid operated brake system, a change speed gearing and shifting mechanism for said gearing, the combination Il' oi a valve in said brake system for holding the brakes applied, and means controlled by the shifting mechanism to render said valve inoperative.

5. In combination with the clutch mechanism, 4o' the iiuid braking system and the change speed transmission of a motor vehicle, a valve in'said braking system for holding the brakes applied, and a pair of independently operable means for controlling said valve, one of said means being 4l;

controlled by the clutch mechanism and the other of said means being controlled by an element of the transmission.

6. In a motor vehicle provided with a clutch mechanism, a iluid braking system, a change so' speed gearing and a gear shitting rod for said gearing, the combination of means in said brake system for holding the brakes applied, means operable by the clutch mechanism for controlling the first named means, and means operated` by 55'.

the shifting rod to render the ilrst named means inoperative.

7. In a motor vehicle provided with a clutch mechanism, a fluid braking system, a change speed gearing and a gear shifting rod i'or select- 00 ing the highest gear ratio oi' the gearing, the combination of a valve in said brake system for holding the brakes applied, means comprising a cam for closing said valve when the clutch mechanism is operated for disengaging the clutch. 55 and cam means operated by the shifting rod when the gearing is in its-highest speed'ratio position for holding said valve in open position.

8. In combination with the clutch mechanism,

the brake mechanism, and the change speed 1ro` tion to render said holding means inoperative 2s,

while said clutch mechanismis in disengaged position.

9. In combination with the clutch mechanism,

means for holding the brakes applied, operative connections between said holding means and the clutch mechanism and between the holding means and the transmission mechanism, said holding means beingcplaced in an operable position by said operative connections when the clutch is in its disengaged position and the elements of the transmission are in a selected speed relation, and being placed in an inoperable position by said connections when the clutch is in its disengaged position and the elements of the I transmission are in another selected speed relation. i

WALTER R. FREEMAN. 

